GREAT CANADIAN PROJECTS
TANGENT PILE
WALL AND
DCP GROUND
ANCHORS
Permanently stabilizing
a failing slope
Submitted by Doublestar Drilling
In early January 2016, Doublestar Drilling (DSD) was award-ed
the Daishowa – Slide Repair Tangent Pile Wall Project.
The purpose of the pile wall was to permanently stabilize
the slope that was failing, causing damage and the poten-tial
closure of Highway 986 North of Peace River. DSD was re-sponsible
for installing 118 cast-in-place concrete piles, 1,200
mm in diameter, to depths of 28.5 metres. Due to soil con-ditions,
each pile required segmental casing up to 15.0mbg
to prevent sloughing and soil loss. DSD’s Liebherr LB36 and
LB28 drill rigs were used to install the piles.
By the middle of March 2016, DSD completed the piling
portion of the wall and began installing the deepest row of
permanent DCP anchors, to a depth of 37 metres. In total,
there were 354 anchors to a combined length of 11,192
metres. Solid and hollow stem auger drilling systems were
required due to highly variable soil conditions on the proj-ect.
Anchor rows two and three required coring through the
1,200-mm cast-in-place piles at a 30-degree angle. DSD’s two
Davey Kent 725 and Soilmec SM-14 drill rigs were used to
PHOTOS COURTESY OF DOUBLESTAR DRILLING
PILING CANADA 67